Indole

117.14800

117.15

204-420-7

8724FJW4M5

1964

DTXSID0020737

LEAFLETS (WATER, PETROLEUM), CRYSTALS (ETHER)|Colorless to yellowish scales, turning red on exposure to light and air.|WHITE CRYSTALLINE SOLID|Colorless, shiny flakes

2933990090

15.79000

2.1

Solid

1 x 10^-6 g/cm³ @ Temp: 25 °C

52 °C

128-133 °C @ Press: 28 Torr

136ºC

1.68

H2O: 2.80 g/L (25 ºC)

2-8ºC

0.0298mmHg at 25°C

LD50 orally in rats: 1 g/kg (Smyth)

ALMOST FLORAL ODOR WHEN HIGHLY PURIFIED, OTHERWISE EXHIBITS CHARACTERISTIC ODOR OF FECES

1.54e-10 cm3/molecule*sec

pKa (basic)= -2.4

121 Ų [M+H]+ [CCS Type: DT, Method: single field calibrated with Agilent tune mix (Agilent)]|117.08 Ų [M-H]- [CCS Type: DT, Method: single field calibrated with Agilent tune mix (Agilent)]

CONGEALING POINT: MORE THAN 51 °C (AFTER BEING DRIED OVER SULFURIC ACID)|Enthalpy of vaporization= 597.5 kJ/kg from 10.3 to 27.4 °C|hydroxyl radical rate constant = 1.54X10-10 cu-cm/molc sec @ 25 °C

3.650 kJ/kg at 25 °C

III

9

UN 2811 6.1/PG 3

1

R21/22; R36

S26-S36/37/39

NL2450000

Xn

Stable, but may be light or air sensitive. Incompatible with strong oxidizing agents, iron and iron salts.

P261-P273-P280-P305 + P351 + P338-P312

H302-H311-H315-H318-H335-H400

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

UN 2811 6.1/PG 3

P261; P273; P280; P305 + P351 + P338; P312

|Danger|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P280, P301+P312, P302+P352, P312, P322, P330, P361, P363, P405, and P501|Aggregated GHS information provided by 1854 companies from 19 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P280, P301+P312, P302+P352, P305+P351+P338, P312, P322, P330, P337+P313, P361, P363, P405, and P501

Indole was detected in industrial wastewaters from the following industries: timber products, leather tanning, iron and steel manufacturing, inorganics and plastics, synfuels, and publicly owned treatment works(1). Process water derived from the Fischer Assay retorting of oil shale from Rundle, Australia contained indole at 3 mg/l(2). A grab sample of final effluent from the Addison, IL publicly-owned treatment works in April 1980 contained indole at unreported concns(3). Wastewater obtained during the gasification of Indian Head lignite contained indole at an estimated concn of 1 mg/l(4). Wastewater and sludge from the Iona Island Sewage Treatment plant, Vancouver, British Columbia contained indole at unreported concns(5).|Untreated coke plant wastewater contained indole from 23 to 26,000 ug/l(1). Volatile components in poultry manure contained indole at concns of 5.08 and 10.4 mg/kg(2). Indole was identified in creosote oil extracts at 7700 ug/g(3). Basin floodwater, taken from Fort Devens, MA, following primary treatment, contained indole at 11 ug/l(4,5). Chlorinated still bottom extract contained indole at unreported concns(6).

Sediments collected from three creosote-contaminated sediment samples from Eagle Harbor, Puget Sound, WA contained indole at concns less than 22 ug/g(1).

INDOOR AIR: Indoor air from 11% of the sampled private homes in the Chicago, IL area contained indole at unreported concns (n= 36)(1).|URBAN AIR: Both vapor phase and aerosol fractions of urban air contained indole at unreported concns(1). Indole was identified on aerosols collected from the Southern North Atlantic Ocean at a mean concn of 0.18 ng/cu m(2).

POSITIVE INOTROPIC EFFECTS OF INDOLE ON ISOLATED GUINEA PIG ATRIA WAS ANTAGONIZED BY PROPRANOLOL & PRETREATMENT WITH RESERPINE.

Indole is found as a component of jasmine oil and orange-blossom oil(1).

Indole's production and use as a chemical intermediate(1,2), a perfume fixative(2), a synthetic flavor(3) and its possible use as a kairomone (a volatile chemical released by a plant to attract phytophagus insects - used for insect control of adult rootworms)(4) may result in its release to the environment through various waste streams(SRC). Indole is released directly to the environment as a component of tobacco smoke(5). High-temperature coal tar contains on average just under 0.2% indole(6).

TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated Koc value of 350(SRC), determined from a measured log Kow(2) and a recommended regression-derived equation(3), and a measured Koc of 187 from a synthetic soil with 0-2% added humic acid(4), indicate that indole will have moderate mobility in soil(SRC). Volatilization of indole should not be important from moist soil surfaces(SRC) given an estimated Henry's Law constant of 5.3X10-7 atm-cu m/mole(SRC), calculated from experimental values for vapor pressure(5) and water solubility(6). Indole is expected to readily biodegrade under both aerobic and anaerobic conditions in soil(SRC). Indole, added to Chernozem soil at 1 and 10 g/kg soil, was completely biodegraded in 19 and 135 days, respectively(7). Indole was completely biodegraded by suspensions of an organic soil (Carlisle muck) under methanogenic and denitrifying conditions within 67 and 144 days, respectively; oxindole was reported as a metabolite of this process(8).|AQUATIC FATE: Based on a recommended classification scheme(1), an estimated Koc value of 350(SRC), determined from a measured log Kow(2) and a recommended regression-derived equation(1), and a measured Koc value of 187(3) indicate that indole may adsorb to suspended solids and sediment in water(SRC). Indole is not expected to volatilize from water surfaces(1,SRC) based on an estimated Henry's Law constant of 5.3X10-7 atm-cu m/mole(SRC), calculated from experimental values for vapor pressure(4) and water solubility(5). According to a classification scheme(6), an estimated BCF value of 25(1,SRC), from a measured log Kow(2), suggests that bioconcentration in aquatic organisms is low(SRC). Indole is expected to readily biodegrade under both aerobic and anaerobic conditions in water(SRC). At 10 °C, aerobic groundwater containing a mixture of aromatic compounds completely biodegraded indole in 310 hours, including an acclimation period of 130 hours(7). Complete metabolism of indole by methanogenic sediments from the shore, edge, and bottom of Buffalo Run stream, PA, occurred within 33 days; oxindole was formed during this process(8). Indole was completely biodegraded under denitrifying conditions in 7 days using a sewage inoculum(8).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), indole, which has a measured vapor pressure of 0.0122 mm Hg at 25 °C(2), will exist solely as a vapor in the ambient atmosphere. Vapor-phase indole is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals, nitrate radicals, and ozone(SRC); the half-lives for these reactions in air are estimated to be about 2 to 3 hours, < 1 minute, and 6 hours, respectively(3,SRC).

The rate constant for the vapor-phase reaction of indole with photochemically-produced hydroxyl radicals has been measured as 1.54X10-10 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 2 to 3 hours at an atmospheric concn of 5X10+5 hydroxyl radicals per cu cm(1,SRC). The main product of this reaction is 2-formylformanilide(1). The rate constant for the vapor-phase reaction of indole with NO3 radicals has been measured as 1.3X10-10 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of < 1 minute at an atmospheric concn of 5X10+8 nitrate radicals per cu cm(1,SRC). The rate constant for the vapor-phase reaction of indole with NO2 radicals has been measured as <2X10-19 cu cm/molecule-sec at 25 °C(1). The rate constant for the vapor-phase reaction of indole with ozone has been measured as 4.9X10-17 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 6 hours at an atmospheric concn of 7X10+11 ozone molecules per cu cm(1,SRC). Products of this reaction are 2-formyl-formanilide and 2-aminobenzaldehyde(1). This compound will exist mainly in the unionized form at environmental pH values based on a pKa of - 2.4(2).|Neutral azaarenes are known to be photosensitive(1). At a concn of 3.14 mg/l a half-life of 19 hours was reported for indole in an aqueous coal-oil mixture exposed to sunlight; actinometer-normalized photolysis rate constants of 0.18 and 0.25 /hr were reported for indole in distilled water and an aqueous coal-oil mixture, respectively(1).

An estimated BCF value of 25 was calculated for indole(SRC), using a measured log Kow of 2.14(1) and a recommended regression-derived equation(2). According to a classification scheme(3), this BCF value suggests that bioconcentration in aquatic organisms is low(SRC).

A Koc of 187 was measured for indole on a synthetic soil consisting of 88-90% sand, 10% clay and 0-2% humic acid(1). The Koc of indole is estimated as approximately 350(SRC), using a measured log Kow of 2.14(2) and a regression-derived equation(3,SRC). According to a recommended classification scheme(4), these Koc values suggest that indole has moderate mobility in soil(SRC).

The Henry's Law constant for indole is estimated as 5.3X10-7 atm-cu m/mole(SRC) from its experimental values for vapor pressure, 0.0122 mm Hg(1), and water solubility, 3560 mg/l(2). This value indicates that indole will be essentially nonvolatile from water surfaces(3,SRC). Indole's Henry's Law constant(1,2,SRC) indicates that volatilization from moist soil surfaces should not occur(SRC).

SURFACE WATER: 1 of 204 surface water samples collected near heavily industrialized areas across the US contained indole at an unreported location and concn(1). Water samples collected from the Adige River, Italy in the Trento province during 1989, contained indole at concns of <10 to 600 ug/l(2).

Different samples of Beaufort cheese from the French Alps contained indole at unreported concns(1). Indole, at unreported concns, was reported as a volatile flavor compound in fried bacon(2), roasted filbert nuts(3), short-necked clams and corbicula(4), and pork(5). Water-boiled duck meat and duck fat contained indole at 1.72 and 2.28 ppb, wet basis, respectively(6).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 6445 workers (4359 of these are female) are potentially exposed to indole in the US(1). Occupational exposure may be through inhalation and dermal contact with this compound at workplaces where indole is produced or used(SRC). The general population will be exposed to indole via inhalation of ambient air, inhalation of tobacco smoke, ingestion of food, and dermal contact with vapors, food and other products such as perfumes containing indole.

4 of 46 human adipose tissue samples, collected in 1982, contained indole (3 in age category 45+, 1 in age category 15-44 years)(1).|PERSONAL AIR: Expired air from control (n= 20), but not prediabetic (n= 14) or diabetic (n= 28) human study populations contained indole at unreported concns(1).

INDOLE UNDERGOES SCISSION OF PYRROLE RING TO YIELD N-FORMYLANTHRANILIC ACID, AN UNSTABLE COMPD WHICH DECOMP INTO ANTHRANILIC ACID & FORMIC ACID. INDOLE IS FIRST HYDROXYLATED TO GIVE INDOXYL & THEN ISATIN, & IT IS PROBABLY LATTER WHICH UNDERGOES HYDROLYTIC RING OPENING.|...INDOLE IS METABOLIZED BY RAT TO INDOXYL, OXINDOLE, 5-HYDROXYOXINDOLE & ISATIN...|YIELDS 2,2-BIS(3-INDOLYL)INDOXYL IN HORSERADISH. DEOXYVIOLACEIN IN CHROMOBACTERIUM. CIS-6,7-DIHYDRO-6,7-DIHYDROXYINDOLE PROBABLY IN PSEUDOMONAS. /FROM TABLE/|YIELDS 3,3'-DIINDOLYLACETIC ACID IN PEA. O-FORMAMIDOBENZALDEHYDE IN TECOMA. 3-HYDROXYOXINDOLE IN COCCUS. /FROM TABLE/|For more Metabolism/Metabolites (Complete) data for INDOLE (10 total), please visit the HSDB record page.|Indole has known human metabolites that include 6-Hydroxyindole, Indoxyl, and Oxindole.

The effects of heterocyclic cmpd on hepatic xenobiotic metabolizing enzymes were studied in mice. Female CD-1 mice were admin 5 u mol/kg coumarin, trimethylene oxide (TMO), or trimethylene sulfide (TMS) for 6 days by gavage, or benzofuran, indole, or indole-3-carbinol (IC) daily for 10 days. Animals were /sacrificed/ 1 or 2 days after the last dose; livers were removed and assayed for epoxide hydrolase, glutathione-S-transferase (GST), reduced NADH-quinone-reductase (NADH/QR), glucose-6-phosphate-dehydrogenase (G6PDH), glutathione-reductase (GSSG-red), uridine-diphosphate-glucose-dehydrogenase (UDPGDH), aniline-hydroxylase, 7-ethoxycoumarin-deethylase (ECOD), and cytochrome-c-reductase (cyt-c-red) activities, and cytochrome p450. All cmpd except indole, significantly enhanced epoxide hydrolase activity. GST activities were elevated by all cmpd except TMO and TMS. NADH/QR activity was incr only by coumarin and benzofuran. Indole incr only GST, UDPGDH and cyt-c-red activities. IC enhanced GST, UDPGDH, cyt-c-red, epoxide hydrolase and cytochrome p450 and related monooxygenase activities. Benzofuran and coumarin showed more varied responses. Both cmpd incr epoxide hydrolase, GST and NADH/QR activities. Benzofuran decr cytochrome p450 content and elevated ECOD activity.

indole

FOUND IN NEROLI OIL IN TRACE QUANTITIES /approx 0.1%/|CONSTITUTES 2.5% OF JASMINE OIL|Technical, CP, FCC

1H-Indole: ACTIVE|REPORTED USES: NON-ALCOHOLIC BEVERAGE 0.26 PPM, ICE CREAMS, ICES, ETC 0.28 PPM; CANDY 0.50 PPM, BAKED GOODS 0.58 PPM, GELATINS & PUDDINGS 0.02-0.40 PPM.|FEMA NUMBER 2593|Adult corn rootworms are attracted strongly to a variety of kairomones, including indole...

SIMULTANEOUS GAS CHROMATOGRAPHIC ANALYSIS OF LOWER FATTY ACIDS, PHENOLS AND INDOLES USING A GLASS CAPILLARY COLUMN.|GAS, THIN LAYER & COLUMN CHROMATOGRAPHY WERE USED TO DETERMINE INDOLE IN FRESH MANURE & ANAEROBIC PIT LIQUOR EXTRACTS.|INDOLES & CARBAZOLES WERE ISOLATED FROM CIGARET SMOKE CONDENSATE BY 4-STEP PROCEDURE WHICH INVOLVED EXTRACTION WITH WATER, SILICIC ACID CHROMATOGRAPHY, GEL FILTRATION CHROMATOGRAPHY & GAS CHROMATOGRAPHY.|A COLLABORATIVE STUDY OF GAS-LIQUID CHROMATOGRAPHIC DETERMINATION OF INDOLE IN SHRIMP.|For more Analytic Laboratory Methods (Complete) data for INDOLE (12 total), please visit the HSDB record page.

THE DETECTION, IDENTIFICATION AND MEASUREMENT OF INDOLE, TRYPTAMINE AND 2-PHENETHYLAMINE IN PUTREFYING HUMAN TISSUE. DETERMINATIVE PROCEDURES: GAS CHROMATOGRAPHY, SPECTRAL, & MASS SPECTRAL METHODS.

EPA Safer Chemical Functional Use Classes -> Fragrances|Safer Chemical Classes -> Yellow triangle - The chemical has met Safer Choice Criteria for its functional ingredient-class, but has some hazard profile issues|Food additives -> Flavoring Agents|Flavoring Agents -> JECFA Flavorings Index

Flavoring Agents